Telecommunications system

Abstract: A telecommunications system is required by the system operator to have a high availability, especially in so far as the central processing is concerned, as failure of this can render a significant portion of the system inoperative. A telecommunications system has connected to an interface at least two remotely attached computing platforms, each of which is arranged to receive, process and provide a response to each functional request from the interface, the system responding to the first response received from the computing platforms. The computing platforms may provide high availability, while themselves being low availability devices.

Description: A telecommunications system is required by the system operator to have a high availability, especially in so far as the central processing is concerned, as failure of this can render a significant portion of the system inoperative. IBM Technical Disclosure Bulletin, Vol. 28, No. 8, January 1986, Pages 3272- 3273, "Parallel processor architecture to control multiple independent telecommunications switching nodes" describes a parallel processor architecture which permits the use of many smaller processors to do the job that once required a larger, more expensive computer. A large telecommunications switching system may be architectured in varying degrees of centralized dependency versus distributed autonomy. Many systems are distributing switching capacity in smaller nodes attached to a central host. All processors in a group may return or initiate a message top any node According to the present invention there is provided a telecommunications system having connected to an interface thereof a plurality of remotely attached computing platforms, each computing platform being arranged to receive, process and provide a response to each functional request received by it from the system interface, characterised in that each functional request is directed to all of the plurality of computing platforms and that the system responds to the first response received from the plurality computing platforms. Preferably, the computing platforms are low availability platforms. The present invention will now be described, by way of example, with reference to the accompanying single figure, in which is shown a possible minimum configuration for Mirrored Asynchronous Processing (MAP). In a telecommunications system having additional adjunct or remote processing the high availability of the system is maintained by mirroring the functional interface requests and discarding the redundant responses. Currently most of the telecommunications systems manufactured are of the stored programme control (SPC) type, i.e. they feature a central processing unit (CPU). The trend with the Intelligent Network concept is to move the processing of services to the centre of a telecommunications network. Mirrored Asynchronous Processing (MAP) is a functional protocol which allows telecommunications processing to be centralised onto a plurality of standard and hence potentially cheap, computing industry platforms, which individually may exhibit a relatively low availability, whilst retaining the telecommunications system high availability. Of course where high availability computing platforms are used the system availability can be increased dramatically, which is advantageous for example for applications where a high level of security is necessary. The computing platforms may be located locally and accessed via a Local Area Network (LAN), or remotely and accessed via a Wide Area Network (WAN). Irrespective of the actual physical interface the MAP functional interface requires that the use of a single physical interface is redundant (at a minimum it should be duplicated). The MAP functional interfacing technique is a request-response based protocol and demands that the high availability telecommunications system controls the requests, irrespective of the origin of the request. The fault detection and reporting procedures are also based on the high availability telecommunications system. The key features of the MAP functional interfacing technique are: the mirroring of the functions of the interface in terms of the requests and responses by the high availability telecommunications system, the asynchronous processing of the requests by the attached low availability computing platforms, discarding of the mirrored (redundant) response (a response may also be checked for accuracy) by the high availability telecommunications system, and, fault detection and reporting based on overdue (or inaccurate) response by the high availability telecommunications system. The figure illustrates a high availability telecommunications system interfacing to a minimum of two remote low availability computing platforms. Each platform is required to run a duplicate of the same application software and to have a minimum of two separate physical interfaces and interface controllers. It is proposed that the telecommunications system controls the MAP functional interface protocol to the remote computing platforms and, in this example, shall: 1. send each "request" to both computing platform #P and its mirror computing platform #P' uniquely identifying each "request" with a MAP identifier, 2. forward the first identified "response" to the telecommunications system 'user' of the MAP interface and discard the mirrored "response" (if received), 2A. optionally, compare the first identified "response" with the mirrored "response". 3. detect failure of #P or #P' to respond within a timed period, by maintaining an image of "responses" due, and report that failure (so that repair may be instigated), 4. ensure periodically that a test procedure is run to ensure that all remote application computing platforms are capable of a response. The low availability application computing platforms shall, in this example: 1. asynchronously process each "request", 2. correlate the "request" with the MAP identifier, 3. respond by including the MAP identifier in the appropriate "response".

Claims: A telecommunications system having connected to an interface thereof a plurality of remotely attached computing platforms (#P,#P'), each computing platform (#P,#P') being arranged to receive, process and provide a response to each functional request received by it from the system interface, characterised in that each functional request is directed to all of the plurality of computing platforms (#P,#P') and that the system responds to the first response received from the plurality of computing platforms (#P,#P'). A telecommunications system as claimed in Claim 1, wherein the computing platforms (#P,#P') are low availability platforms. A telecommunications system as claimed in Claim 1 or 2, wherein the system monitors the functionality of all the computing platforms (#P,#P') by identifying the response if any from each further computing platform (#P,#P') and comparing the response with the first response. A telecommunications system as claimed in Claim 1, 2 or 3, wherein the system includes an Intelligent network.

Inventors: JONES KEITH PATRICK, JONES, KEITH PATRICK
Applicants: MARCONI UK INTELLECTUAL PROP, MARCONI UK INTELLECTUAL PROPERTY LTD
Application year: 1994
Main classification: H04Q3
IPC codes: H04Q3, G06F13